Genome: The Autobiography of a Species in 23 Chapters

HSoon we'll know what's in our genes: next year, the Human Genome Project will have its first-draft map of our 23 chromosomes. Ridley (The Red Queen; The Origins of Virtue) anticipates the genomic news with an inventively constructed, riveting exposition of what we already know about the links between DNA and human life. His inviting prose proposes ""to tell the story of the human genome... chromosome by chromosome, by picking a gene from each."" That story begins with the basis of life on earth, the DNA-to-RNA-to-protein process (chapter one, ""Life,"" and also chromosome one); the evolution of Homo sapiens (chromosome two, which emerged in early hominids when two ape chromosomes fused); and the discovery of genetic inheritance (which came about in part thanks to the odd ailment called alkaptonuria, carried on chromosome three). Some facts about your life depend entirely on a single gene--for example, whether you'll get the dreadful degenerative disease Huntington's chorea, and if so, at what age (chromosome four, hence chapter four: ""Fate""). But most facts about you are products of pleiotropy, ""multiple effects of multiple genes,"" plus the harder-to-study influences of culture and environment. (One asthma-related gene--but only one--hangs out on chromosome five.) The brilliant ""whistle-stop tour of some... sites in the genome"" passes through ""Intelligence,"" language acquisition, embryology, aging, sex and memory before arriving at two among many bugbears surrounding human genetic mapping: the uses and abuses of genetic screening, and the ongoing debate on ""genetic determinism"" and free will. Ridley can explain with equal verve difficult moral issues, philosophical quandaries and technical biochemistry; he distinguishes facts from opinions well, and he's not shy about offering either. Among many recent books on genes, behavior and evolution, Ridley's is one of the most informative. It's also the most fun to read. Agent, Felicity Bryan. (Mar.)